Condition when subscribers in NServiceBus send an auto-subscribe message

Question

I am finding out that even when my NSB process does not handle messages for say DTOXXX, it is still sending an auto-subscribe message to the publisher queue for DTOXXX.

This is not the desired behavior. I want the process to publish and subscribe to messages for DTOYYY, but any communication using DTOXXX is strictly send only.

If that wasn't clear enough I have 2 assemblies that contains my DTO. I Want to establish a pub/sub bus, but only for assemblies in YYY.dll. As for the DTOs in the other assembly, I want the communication to be done via SEND only (not pub sub).

The problem I am running across is that NSB is sending auto subscribe message to the other process even though:

1. There is no handler for the DTOs in the XXX assembly. It's being referenced only so that YYY NSB can send messages to XXX NSB.
2. The communication between the 2 modules are strictly SEND only. This is done to promote low coupling given the actual use case & biz requirement.

How can I set up my modules properly? That is I need to somehow tell NSB, to auto subscribe for messages but only for the ones in a given namespace/assembly.

Answer 1

You can define your own rules for which messages are considered commands/events (or plain messages) by implementing your own DefiningEventsAs in the configure interface. Nsb will only autosubscribe to events. That may help you for your usecase...

Answer 2

There are a couple of ways to handle this, the first being that you can turn of auto-subscribe and subscribe manually. This is done via .DoNotAutoSubscribe() in you endpoint config. From there you will resolve and instance of IBus and then subscribe explicitly to the messages you care about.

The second way is to separate your messages from all other code into different assemblies and only map the events(pub/sub) to the Publisher via the app.config file.